Optical information recording/reproducing apparatus having focus servo control compensation for lands and grooves
US5999502A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1995 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Oct 6, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10576
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an optical information recording-reproduction apparatus, a focus servo control circuit generates a focus error signal and a light beam is accurately converged on a surface of an optical disk according to a focus servo control signal based upon the focus error signal. In accordance with the present invention, the focus error signal is compensated by selecting a land section focus offset amount by a switch when land sections are tracked, and it is compensated by selecting a groove section focus offset amount when groove sections are tracked. As a result, since the land sections and the groove sections are controlled by different focus servo control signals, recording and reproducing operations are carried out at the most optimal focusing positions respectively obtainable, thereby making it possible to significantly improve the quality of a reproduced signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.